Doc on a Hot Tin Roof

I've been studying my part - the doctor in Cat.

Based on the play alone, you would guess that Tennessee Williams did not exude trust toward doctors. And his biography suggests reasons why:

Tennessee was close to his sister Rose, a slim beauty who was diagnosed with schizophrenia at a young age... Williams' parents authorized a prefrontal lobotomy. ...the operation incapacitated Rose for the rest of her life.

Her surgery may have contributed to his alcoholism and his dependence on various combinations of amphetamines and barbiturates often prescribed by Dr. Max (Feelgood) Jacobson.

The real life Dr. Feelgood was quite the character:

...Jacobson was known for his "miracle tissue regenerator" shots which consisted of amphetamines, vitamins, painkillers, and human placenta.

One doctor wrecked his sister's brain.
One shot him up with dubious stuff.

If it's distrust that you want to explain,
that's explanation enough.